Lufthansa German Airlines / cancellation of flight

Hai I booked for a flight to istanbul, turkey on 15/01/2019. And I was notified of the cancellation of flight just a day before. So I requested for a full refund and haven't got any. I booked lufthansa flight through mytrip.com and I contacted their customer care several times but in vain. My booking order number: ksqhh1.
The booking number/air ref. Is rzc7cj / lh.